Improvement in balanced slide-valves



Patented May 7,1872.

aamvs's Pnocssag UNITED STATES PATENT QEEICE.

ALLAN STIRLING, OF TROY, NEW YORK.

IMPROVEMENT IN BALANCED SLIDE-VALVES.

To all whom it may concern:

Be it known that I, ALLAN STIRLING, of Troy, in the State of New York, have invented a new and useful Improvement in the Construction of Balanced Slide-Valves of Steam- Engines when the valve is balanced by a piston connected with it, operating in a cylinder at or near right angles with the face of the valve, the inner surface of the piston being exposed to the pressure of steam in the steamchest.

My improvement consists, first, in constructing therod connectingthe valve with the piston in two parts, having a central joint, the pivot or pin of which is at right angles with the pins on either end, so as to secure a self-adjusting suspension to the valve and piston.

This arrangement for balancing the valves may be used with or without cut-offs.

To enable others skilled in the art to make and use' my invention, I will proceed to describe its construction and operation.

Figure l is a vertical longitudinal section. Fig. 2 is a vertical transverse section. Fig. 3 is a plan View. Fig. 4 is a detail view, on an enlarged scale, showing the connection between the slide-valve and the piston-rod.

I construct my valve C and balancing-piston D and cylinder F in the usual way; but, in order to allow the valve to adjust itself to the seat, I make the connecting-rod between the valve and piston in two pieces, jointed together by a transverse joint, as shown at A A; and in order to reduce the friction and wear of the journals, I make the pins and bushes at the ends of the connecting-rod, as shown at B or E, so that the connecting-rod rolls, but does not slide on the pins.

I do not claim the use of abalancing-piston in connection with a slide-valve, for the same has been in use before. My invention relates only to improvements thereon.

What I claim as my invention, and desire to secure by Letters Patent, is-

The valve O and balancing-piston D, connected by a rod which has a central joint, the pivot of which stands at right angles to its bearings E and B, at either end substantially as and for the purpose specified.

ALLAN STIRLING.

Witnesses RicnARn DAvmsoN, Tnos. B. Cook. 

